The dose calculations are carried out by following the guide- lines of USNRC Regulatory Guide 1.109.
Radiation exposure for maximum individuals and population are estimated within 30 km from the nuclear plant. This area is divided into 160 circular trapezoids, to which computations are referred.
Four age groups, seven organs for internal dose and two for external dose have been considered.
Dose calculations are done through 14 pathways, 7 for liquid effluents, one for noble gases, and 6 for the rest of gaseous effluents.

EDO consists of a main program and 8 sub- routines for calculations. Running time for a case which considers all the subroutines, 46 nuclides (liquid effluents), 12 nuclides (gaseous effluents) and 11 noble gases, is about 26 minutes, of which 1 minute 20 seconds are CPU time.
NEA-DB executed the test case included in the package (NEA 0845/01)
on UNIVAC 1110 in 145 seconds of CPU time.

Main storage: 46 kwords on UNIVAC 1100 series computer, when segmentation MAP program is used.
8 blocks on tape or 8 tracks of mass storage for 6 files containing constant data input. Two of these files must be direct access files.
FORTRAN V standard system library functions.
I/O devices: card reader and printer.

Due to memory requirements, the programs are linked using a segmented MAP. Users on other computers than UNIVAC are advised to adhere to the overlay structure, listed in the MAP program.
Also, in order to reduce main storage, dose factor data for ingestion and inhalation are recorded as direct access files.